The most captivating player in baseball right now rarely picks up a bat. He doesn't have much use for his glove, and he has never thrown a pitch.
Billy Hamilton
runs. And because he runs faster than just about anyone else in the sport, the Cincinnati Reds rookie has become a threat unlike any other.

Even before his major-league debut last week, Hamilton's speed was the stuff of renown. He set a single-season record with 155 steals in the minor leagues last year. But the legend grew when Hamilton, 23, became the first player since 1921 to steal four bases and score three runs without making a single plate appearance in his first four major-league games. All three runs either tied or won a game for the Reds, who are locked in a tight, three-way race to win the National League Central.

"That's what speed does," Hamilton said.

In terms of its impact on a team's probability of winning, pinch running is regarded as one of the least significant elements of baseball. But at Great American Ballpark, Hamilton has made it an event within an event.

When he replaces a runner at first base, he creates a stir comparable to that of an elite closer or a fearsome pinch hitter entering a game. The crowd erupts. Infielders walk to the mound, offering words of reassurance to the pitcher. Instead of the customary boos, attempts to pick off Hamilton elicit more cheers.

It is a rare sight in an era with few elite speedsters, especially in a season in which stolen bases are down nearly 17% from 2012.

The last Billy Hamilton to play in the majors made his debut in 1888 for the Kansas City Cowboys. He went on to steal more than 900 bases (the precise number is in dispute), earning the nickname Sliding Billy and a spot in the Hall of Fame.

In time, the Reds hope Hamilton can become a lighter-hitting version of his namesake, well rounded enough to play center field and hold his own at the plate. But for now, he is essentially a designated runner.

Whatever time Hamilton gets at the plate or in the field is likely to come only late in blowouts such as Tuesday's 9-1 loss to the Chicago Cubs, in which Hamilton went 0 for 2. He was hitting .256 this year in Triple-A.

"His hitting needs to improve," Reds manager Dusty Baker said.

That the Reds can benefit from Hamilton's nearly unparalleled strength as a runner without exposing his liability at the plate shows how advantageous September roster rules can be to teams with specialists in their farm system.

On Sept. 1, the roster limit expands from 25 to 40 players. The rule, which has become somewhat controversial in recent years, allows a manager to use players with one particular asset—usually a pinch runner, defensive replacement or bullpen specialist—in narrowly defined roles without depleting his bench. Under normal roster rules, Reds general manager Walt Jocketty said, Hamilton "most likely would not be here."

It is tempting, when caught up in the aura of Hamilton, to wonder if such a role would ever make sense over a full season. Baseball history is dotted with September call-ups who have been used primarily as pinch runners. But only one team has ever experimented with a true, full-time designated runner.

In 1974, Oakland A's owner Charlie Finley signed Herb Washington, a track star with almost no baseball experience. In parts of two seasons, he stole 31 bases and scored 33 runs without ever coming to bat or playing the field. But he was caught stealing 17 times, and Oakland released him one month into the 1975 season. (Hamilton has yet to be caught in the majors.)

"Baseball folks are slow to that kind of change," Washington said in an interview this week. "You need to have a very progressive-minded owner or manager, and Charlie Finley was that kind of guy. He recognized what speed can do in a ballgame. Everyone loves speed."

But on this issue, both traditionalists and iconoclasts agree: If a player does little more than pinch run, however well, he isn't worth his uniform.

"This innovation has been tried dozens of times by many different clever people, and it has always failed," said Bill James, the godfather of advanced baseball research and a Boston Red Sox senior adviser. "And I think it always will fail, for a simple reason: It doesn't deliver a large enough benefit."

Speed, James said, is more valuable in the field, which is why the evolution of Hamilton's defense is so important to Cincinnati. Jocketty said Hamilton was arguably the best defensive center fielder in the International League this year. "There's really more to his game," he said. "I hope everyone gets to see that at some point."

But for now, the Reds don't need Hamilton to do more than create havoc on the base paths. He may do it with a steal or taking an extra base. He can also do it just by distracting pitchers.

"He keeps the opposition on edge all the time," Jocketty said, "which is what the purpose is, really."

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